The seven identified as Aman Pratap Singh alias Nanhe, Jitendra Jaiswal, Rohit Singh, Roshan, Mohit Verma, Pradeep Seth and Ashutosh Tripathi were arrested from Saidpur area in Ghazipur, ADG Police Arun Kumar told reporters.
The ADG said that on December 7 the gang shot dead jeweller Ajay Barnwal (50), who was also vice-president of SP Vyapaar Sabha and his brother Vijay Barnwal (40) in Saidpur and escaped with cash and jewellery.
Nanhe and Rohit were B Tech students, the police official said.
Six fire-arms, including two 9 MM pistols, Rs 1.29 lakh cash, a bag containing jewellery and 15 mobiles with sim cards were seized from their possession, he said.
Last week, the gang members had shot dead one Rinku and looted a .32 bore pistol, he said.
On October 27, the gang had killed one Bachche Lal in Karanda area, Kumar said.
